1. Field of the Invention
This invention relates to mucosal adhesives. In another aspect this invention relates to compositions that adhere to oral mucosa. In yet another aspect this invention relates to methods of transmucosal drug delivery.
2. Description of the Related Art
Buccal tablets and like devices are known and disclosed for example in U.S. Pat. Nos. 4,740,365 and 4,764,378. These devices adhere to mucosal surfaces and dissolve or otherwise disintegrate over time, thus delivering drug into the mouth of the patient in a sustained fashion. It is also known that delivery of drugs across the oral mucosa avoids hepatic first-pass inactivation, inactivation by gastro-intestinal fluids, and other modes of inactivation characteristic of oral drug ingestion. Sustained release adhesive bandages, patches, and the like that contain drugs and adhere to mucosal surfaces are known to the art. Polyacrylic acids and polyisobutylenes have been disclosed as components of such adhesives. For example, U.S. Pat. No. 3,339,546 (Chen) discloses a bandage that is said to adhere to moist surfaces of the oral cavity and comprises a medicament and a hydrocolloid incorporated in a natural or synthetic gum-like substance. Carboxypolymethylene (i.e., polyacrylic acid) is among the hydrocolloids disclosed, and polyisobutylene is among the gum-like substances disclosed.
U.S. Pat. No. 4,615,697 (Robinson) discloses a composition including a bioadhesive and a treating agent. The bioadhesive is a water-swellable but water insoluble, fibrous, crosslinked, carboxy-functional polymer containing (a) a plurality of repeating units of which at least about 80% contain at least 1 carboxy functionality, and (b) about 0.05 to about 1.5% of a cross-linking agent substantially free from polyalkenyl polyether. The specifically excluded type of crosslinker is said to be the type used in CARBOPOL™ 934 resin (commercially available from B. F. Goodrich, Specialty Chemicals and Polymers Division, Cleveland, Ohio). CARBOPOL™ 934 resin is said to be water soluble and therefore undesirable as a bioadhesive in the Robinson composition.
U.S. Pat. No. 4,253,460 (Chen et al.) discloses an adhesive composition consisting of a mixture of a hydrocolloid gum, a pressure sensitive adhesive, and a cohesive strengthening agent. The pressure sensitive adhesive component can be a mixture of three to five parts of a polyisobutylene with a viscosity average molecular weight of about 36,000 to about 53,000 and one part of an elastomer such as a polyisobutylene with a viscosity average molecular weight of about 1,150,000 to about 1,600,000.
U.S. Pat. No. 4,740,365 (Yukimatsu et al.) discloses a sustained-release preparation comprising an active ingredient and a mixture of two polymer components, the first of which comprises one or more polymers selected from polyacrylic acid and a pharmaceutically acceptable salt thereof, and the second being selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, alginic acid, and a pharmaceutically acceptable salt of alginic acid. CARBOPOL™ resins are among the polymers said to be suitable members of the first-mentioned class of polymers.
U.S. Pat. No. 4,772,470 (Inoue, et al.) discloses an oral bandage comprising a mixture of a polyacrylic acid and a vinyl acetate polymer in a compatible state. This bandage is said to exhibit strong adhesion of long duration when applied to oral mucosa or teeth.